#include <iostream>
#include <string>


int main()
{
  std::string s1("hello");
  std::string::iterator it = s1.begin();

  while(it != s1.end())
  {
    std::cout<< *it <<std::endl;
    ++it;
  }

  std::cout<<std::endl;

  for(auto it:s1)
  {
    std::cout<< it <<std::endl;
  }

  std::cout<<std::endl;
  return 0;
}
